The invention relates to a rock drilling rig comprising a boom provided with a rock drilling machine, as well as a pressure medium system having actuators connected to it. The rock drilling rig is moved by means of combustion-engine-free drive equipment comprising at least one electric drive motor, as well as power transmission members between the drive motor and the traction wheel. In transfer drive, electric energy to be used may be charged in an energy storage included in the electric system. The drive motor serves as a generator and a primary brake in long-term downhill driving, and generated electric energy is controlled to charge the electric storage.
Further, the invention relates to a method for downhill driving of a rock drilling rig.
The field of the invention is described in more detail in the preambles of the independent claims of the application.
In mines, rock drilling rigs are used to drill boreholes at planned drilling sites. When the boreholes have been drilled, the rock drilling rig is transferred to the next drilling site for drilling a new drilling fan or face. In particular, in underground mines it is advantageous to perform the transfer drive by means of power generated by an electric motor. The energy required by the transfer drive may be stored in a battery. In mines, there is also frequently a need to drive the rock drilling rig along drive ramps sloping downwards. In large mines, downhill driving may even take a very long time. For the duration of downhill driving, the electric drive motor is connected to serve as a generator, the electricity generated by this generator being used to charge the battery. However, during long-term downhill driving, such a large amount of electric energy is generated that not all of it can be used for charging batteries. Thus, the electric system of the rock drilling rig has a limited capability to control the generated electric energy, which may make efficient downhill driving more difficult.